You are using the path finding a bit wrong.
The way you can think of the path finding behaviour is by following these steps:
1. Find path
2. Path found -> Move along path
3. Path not found -> do something else, could be to try to find a new path or whatever.
This is something that is handle in the background of C2 so your game will actually continue running while the path is found (calculated)
Therefore you would normally use the "Find path" based on some conditions, like a unit having reached its destination and needing a new path or you could make it trigger based on a state machine, mouse click if its a strategic game and so forth.
Once the "Find path" have found an calculated a path this event will trigger. The reason I call it a trigger is because you will notice that when you add it, it have a small green arrow to the left of it. All events or almost all event with such arrow are triggers, there are some events which look like they are triggers, but ain't (think its a bug). But as a general rule a green arrow means an event is a trigger. This means they will "activate" once a certain condition occurs, in this case it will trigger once a path have successfully been found.
Since its a trigger it needs to be placed on the top level or as a starting condition.